In today's modern society, cooling processes play an important role both in industrial and individual contexts. However, there have recently arisen concerns regarding the use of certain "working fluids" which are used in refrigeration and other cooling processes. Certain organic liquids, such as dichloro-diflouoromethane, have been associated with the destruction of the ozone layer and the attendant warming of the earth by the "greenhouse effect". Because of the potential dangers associated with the use of these "working fluids", alternative cooling processes have been developed.
An alternative cooling process which has recently gained favor involves the use of thermoelectric devices which function as a heat pump by the Peltier principle. These thermoelectric devices comprise a circuit of an N-type semiconductor and a P-type semiconductor joined electrically at one end to form a couple. These couples are joined together electrically in series to form a multicouple device that serves as a solid state heat pump.
However, several problems are associated with the use of thermoelectric heat pumping devices. The efficiency of conventional thermoelectric heat pumping devices tend to be fairly low and a figure-of-merit (Z) of approximately 2.3-2.5.times.10.sup.-3 /.degree.K. are typical. The figure-of-merit (Z) is defined as .alpha..sup.2 .sigma./K, wherein .alpha.=Seebeck coefficient=.mu.V/.degree.K.; .sigma.=electrical conductivity=(.OMEGA.cm).sup.-1 ; and K=thermal conductivity=mW/cm .degree.K.
Another problem associated with conventional thermoelectric heat pumping devices is their fragility, i.e., low compressive, shear and tensile strengths. Conventional thermoelectric modules comprise crystalline grown, sliced and diced semiconductor elements which contain classic cleavage planes which are held together by weak Vander Waal bonds. Accordingly, they are subject to failure in applications involving vibration, temperature cycling, shock and high thermal stress. Therefore, in order to expand the range of utilization of these thermoelectric cooling devices, there is a need for semiconductor elements having a higher thermal efficiency and improved mechanical properties.